If you play with your Eevee at night too often, its unstable DNA gets crushed by the radiation of the moon, causing some kind of radiation sickness. It loses nearly all of its fur and its sweat gets toxic. everytime a predator tries to hunt it down it starts sweating.
It is a rather harmless Pokémon that nearly never attacks out of aggresion, it either flees or contaminates its foes by sweating.
This time the redesign was much harder but also a lot more fun to draw. Umbreon is just some wacky mutation of eevee. But there are several features that can be found in the real world, too. Moray eels share toxic blood and slimy skin with Umbreon, therefore I tried to make Umbreons head look a little bit like a moray. Then there are its glowing parts. The solution can be found in the deep sea, where the fishies glow in certain areas to communicate or allure prey.
and now I'm tired... uargh